Molding machine squeeze foot



May 4, 1965 E. H. BRAUER MOLDING MACHINE SQUEEZE FOOT Filed Feb. 12, 1962 lNvENToR Edwin H. Brauer lnllllL United States Patent Oliice 3,181,208 MGLDING MACHINE SQUEEZE FOOT Edwin H. Brauer, Zelienople, Pa., assignor to Herman Pneumatic Machine Company, Pittsburgh, Pa., a corporation oi Pennsylvania Filed Feb. 12, 1962, Ser. No. 172,746 2 Claims. (Cl. 22--41) This invention relates to molding machines and more particularly to the squeeze feet mounted in the squeeze head of a molding machine.

The mounting of a plurality of squeeze feet in the squeeze head of a molding machine is well known to those skilled in the molding machine art. Generally speaking, the squeeze head and squeeze feet are disposed above a flask which is filled with molding sand to be rammed about a pattern disposed therein. The squeeze head and/or squeeze feet are lowered to ram the sand and due to the uneven surface of the pattern in the mold, some squeeze feet will be advanced further into the llask than others, the general rule being that the squeeze feet disposed above low pattern areas are advanced further than those disposed over high pattern areas. This irregularity permits sand to Work up or accumulate behind the squeeze feet and from this arises a serious problem of long standing as will now be more fully explained.

Heretofore in molding machines, squeeze feet have been attached to or otherwise were a part of one end of a piston rod, the other end of the piston rod having a piston head in a cylinder by which means each rod and its attached squeeze foot were advanced and retracted in the ramming operation. The aforementioned serious problem attendant the ramming operation has been that the sand that worked its way up past the squeeze foot accumulated on the piston rod, which being wet with lubricant caused the sand to adhere thereto and thus be carried back into the cylinder when the squeeze foot was returned. The sand thus transported would abrade and unduly wear the piston and cylinder walls causing fluid leakage and necessitate the premature replacement of the parts so abraded.

That this has been a problem of long standing in this art is evidenced by the age and number of various devices that have heretofore been proposed to alleviate the problem. For example, Patent No. 382,217 to J. R. Davies provided booties to cover the piston rods; see also the means provided in Patent No. 450,521 to T. Mistelski and Patent No. 346,3 80 to M. R. Moore.

I have invented squeeze foot means which substantially eliminates the aforementioned problem simply and inexpensively without the addition of extra members and elements such as heretofore found necessary.

I provide a multiplicity of squeeze feet mounted in a squeeze head wherein each squeeze foot is mounted on a respective cylinder member discrete from other cylinder members which is movably disposed on a rod member fixed to said squeeze head whereby said cylinder member may be advanced and retracted along said rod member relative to said squeeze head.

I preferably provide that said cylinder member be of a length sufficient to cover said rod member when said cylinder member is fully retracted.

I further preferably provide that said cylinder member have a fluid-tight chamber therein communicating with fluid reservoir means through an axial opening in said rod member whereby fluid may enter and leave said chamber whereby said cylinder member and its respective squeeze foot advance and retract respectively from said squeeze head along said fixed rod member.

I also preferably provide that said cylinder member 3,181,208 Patented May d, 1965 normally be centrally positioned along said rod member and provide centering means adapted to return said cylinder member and its respective squeeze foot to said central position.

Other details, objects and advantages of the invention will become apparent as the following description of a present preferred embodiment thereof proceeds.

In the accompanying drawings I have shown a present preferred embodiment of the invention in which FIGURE l is a general diagrammatic showing of a molding machine having a squeeze head with squeeze feet disposed above a ask;

FIGURE 2 is an enlarged cross-sectional view of a squeeze foot assembly embodying my invention in an advanced position.

FIGURE 3 is an enlarged cross-sectional View of a squeeze foot assembly embodying my invention in central or normal position.

FIGURE 4 is an enlarged cross-sectional View of a squeeze foot assembly embodying my invention in a retracted position.

Referring now to the drawings and initially to FIGURE l, l have there illustrated generaly a molding machine 1 having a squeeze head 2 with a multiplicity of squeeze foot assemblies 3 attached thereto beneath it. A flask 4 is disposed beneath squeeze foot assemblies 3 and contains therein the sand (not shown) to be rammed.

Referring now to FIGURES 2-4, I illustrate a squeeze foot assembly 3 having a squeeze foot 5 which is attached to the cylinder head 6 of the cylinder 7 by suitable means such as the screw 8. Cylinder head 6 may be welded in cylinder 7 or, as shown, held therein by retaining ring 6a. Cylinder 7 in turn is slidably mounted on rod 9 which in turn is fixed at one end therer of to squeeze head 2 by suitable means such as retaining ring 10 and annular shoulder 11. As shown in FIGURES 2 4, rod 9 has an axial opening 12 therethrough, which at the squeeze head end is threaded as at reference 13 for suitable coupling to a tluid reservoir or supply (not shown). The other end of opening 12 terminates in a chamber 14 formed by cylinder head 6, the walls of cylinder 7 and a collar 15 disposed on the end of rod 9. Suitable packing 16 is provided to assure the fluidtight integrity of cylinder 7.

As apparent from FIGURE 4, cylinder 7 is of a length sufficient to cover rod 9 when cylinder 7 is fully retracted toward squeeze head 2. It should be noted that the length of cylinder 7 is such that rod 9 bottoms against cylinder head 6 simultaneously as the upper portion of cylinder 7 meets and bears against squeeze head 2 when fully returned. This adds substantial additional strength to squeeze foot asembly 3 when cylinder 7 is fully retracted as may occur from time to time during the iinal portion of a squeeze cycle sometimes referred to as the final hard squeeze.

It can be readily understood that cylinder 7 and consequently squeeze foot 5 may be advanced from squeeze head 2 by supplying fluid under pressure through opening 12 into chamber 14.

It will be clear to those skilled in the art that even though molding sand may work its way past squeeze foot 5, as shown in FIGURE 2, it will collect, if at all, only harmlessly upon the outside surface of cylinder '7, and consequently will not be carried inside the cylinder to cause fluid leakage through abrasion.

I mount cylinder 7 on rod 9 so that its pre-cycle or normal position is centered thereon as shown in FIGURE 3. This is particularly useful in a molding machine wherein the uid systems of the squeeze feet are manifolded to each other (or in groups) independently of the squeeze head fluid system, so that they hunt or selfadjust to levels of equalized pressure, i.e., the uid system for the squeeze foot assemblies is closed and apart from the squeeze head fluid system and the ramming operation is accomplished by lowering the squeeze head to advance the squeeze feet into the flask for ramming; whereupon, some of the squeeze feet are moved upward or retracted by the pressure from the sand against which they are being pushed by the squeeze head, and the fluid thus displaced from chamber 14 of the respective cylinders will, through the aforesaid manifolded independent system, force other squeeze feet to advance further into the ask and thus hunt to equalize the ramming pressures being applied to the sand.

It is apparent however that my invention is equally applicable and useful in molding machines wherein the normal position of the Squeeze foot assemblies at the beginning of a squeeze cycle would be as shown in FIG- URE 4 in which case the squeeze feet would simply advance during the squeeze operation rather than hunt as above described.

To return squeeze foot assembly 3 to the starting position shown in FIG. 3, I preferably provide a pre-loaded spring 17 which is mounted on rod 9 within cylinder 7 and is retained thereon between the slidable collars 15 and 18 by the retaining ring 19 secured in the lower end of rod 9 and the shoulder 20 of rod 9. Additional rings 21 and 22 are secured in cylinder 7, ring 21 being disposed above collar 18 and ring 22 being disposed below collar 15. It is clear when viewing FIGURES 2, 3 and 4, that when cylinder 7 is advanced from squeeze head 2 the ring 21 engages collar 1S and carries it with cylinder 7 along rod 9 away from squeeze head 2 and thereby compresses spring 17 against collar 15 which is held stationary by retaining ring 19 as shown in FIGURE 2. It is also clear that when cylinder 7 is retracted or moved toward squeeze head 2, as in FIGURE 4, ring 22 engages collar 15 and carries it with cylinder 7 along rod 9 and thereby compresses spring 17 against collar 1S which is held stationary by shoulder 20. Thus, when at the end of a squeeze cycle the pressure'on the squeeze feet is released, the compressed spring 17 in each of the squeeze foot assemblies will exert pressure upon collars 15 and 18 and thus return cylinder 7 to center or normal position regardless of whether cylinder 7 was advanced or retracted relative to squeeze head 2.

I further provide openings 23 and 24 in rod 9 which communicate axial opening 12 with other chambers within the cylinder to permit the iiow of luid in and out of those areas.

While I have shown and described a present preferred embodiment of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied within the scope of the following claims.

I claim:

1. In a molding machine with a squeeze head having a multiplicity of squeeze feet the improvement comprising mounting each of said squeeze feet on a respective cylinder member spaced from other cylinder members which is slidably mounted on a rod member fixed to said squeeze head, means normally maintaining said cylinder member with said squeeze foot in a central position whereby said cylinder member and squeeze foot may be moved upwardly and downwardly along said rod member relative to said squeeze head, said cylinder member being of a length that substantially covers said rod member when said cylinder member is fully retracted toward said squeeze head, said cylinder member having a substantially Huid-tight chamber therein communicating with iiuid reservoir means through an axial opening in said rod member whereby fluid may enter and leave said chamber with said cylinder member thereby advancing and retracting respectively from said central position along said fixed rod member and centering means adapted to return said cylinder members and their respective squeeze feet to said central position.

2. In a molding machine with a squeeze head having a multiplicity of squeeze feet, the improvement comprising mounting each of said squeeze feet on respective rod and cylinder means fixed to said squeeze head, each of said cylinders having a substantially huid-tight chamber therein communicating with uid reservoir means whereby said squeeze feet are movable upwardly and downwardly with respect to said squeeze head, means operable to normally maintain said squeeze feet in a central position with respect to said squeeze head whereby said squeeze feet may be moved both downwardly and upwardly from said central position during a squeeze operation and thereafter be returned to said central position at the conclusion of said squeeze operation.

References Cited by the Examiner UNITED STATES PATENTS 12/48 Young 22--45 11/60 Frankenstein 22-45 

1. IN A MOLDING MACHINE WITH A SQUEEZE HEAD HAVING A MULTIPLICITY OF SQUEEZE FEET THE IMPROVEMENT COMPRISING MOUNTING EACH OF SAID SQUEEZE FEET ON A RESPECTIVE CYLINDER MEMBER SPACED FROM OTHER CYLINDER MEMBERS WHICH IS SLIDBALY MOUNTED ON A ROD MEMBER FIXED TO SAID SQUEEZE HEAD, MEANS NORMALLY MAINTAINING SAID CYLINDER MEMBER WITH SAID SQUEEZE FOOT IN A CENTRAL POSITION WHEREBY SAID CYLINDER MEMBER AND SQUEEZE FOOT MAY BE MOVED UPWARDLY AND DOWNWARDLY ALONG SAID ROD MEMBER RELATIVE TO SAID SQUEEZE HEAD, SAID CYLINDER MEMBER BEING OF A LENGTH THAT SUBSTANTIALLY COVERS SAID ROD MEMBER WHEN 